Abstract

Ethylene governs a range of developmental and response processes in plants. In Arabidopsis thaliana, the
Raf-like kinase CTR1 acts as a key negative regulator of ethylene responses. While only one gene with
CTR1 function apparently exists in Arabidopsis, we have isolated a family of CTR1-like genes in tomato
(Lycopersicon esculentum). Based on amino acid alignments and phylogenetic analysis, these tomato CTR1-
like genes are more similar to Arabidopsis CTR1 than any other sequences in the Arabidopsis genome.
Structural analysis reveals considerable conservation in the size and position of the exons between Arabidopsis
and tomato CTR1 genomic sequences. Complementation of the Arabidopsis ctr1-8 mutant with
each of the tomato CTR genes indicates that they are all capable of functioning as negative regulators of the
ethylene pathway. We previously reported that LeCTR1 expression is up-regulated in response to ethylene.
Here, quantitative real-time PCR was carried out to detail expression for LeCTR1 and the additional
CTR1-like genes of tomato. Our results indicate that the tomato CTR1 gene family is differentially regulated
at the mRNA level by ethylene and during stages of development marked by increased ethylene
biosynthesis, including fruit ripening. The possibility of a multi-gene family of CTR1-like genes in other
species besides tomato was examined through mining of EST and genomic sequence databases.

Item Type:

Article

Additional Information:

The original PDF of the article can be found at Plant Molecular Biology website : http://www.springerlink.com/content/q81q71274u41pm12/
The original publication is available at www.springerlink.com